* TSX ends up 1.8% at 31,883.81

* Posts biggest gain since February 13

* Technology rises 3.4%

* Energy loses 1.3% as oil settles 10.3% lower

(Updates at market close)

By Rashika Singh and Fergal Smith

March 23 (Reuters) - Canada's main stock index rose on

Monday by the most in five weeks, led by gains for technology

and metal mining shares, as fears eased of a major escalation in

the Middle East war.

The Toronto Stock Exchange's S&P/TSX composite index

ended up 566.40 points, or 1.8%, at 31,883.81, its

biggest advance since February 13. On Friday, the index posted

its lowest closing level in three months.

Iran denied that it had engaged in negotiations with the

United States, after President Donald Trump postponed a threat

to bomb Iran's power grid because of what he described as

productive talks with unidentified Iranian officials.

"The broader market remains highly sensitive to shifting

headlines around the Middle East conflict," said Allan Small,

senior investment advisor at Allan Small Financial Group with iA

Private Wealth. "Nobody knows what's going on as mixed signals

from Washington and Tehran continue to whipsaw sentiment."

The technology sector rose 3.4%, with shares of

electronic equipment company Celestica Inc ( CLS ) up 6.6%.

The materials group, which includes fertilizer

companies and metal mining shares, added 3.2%. Copper

prices climbed but the price of gold was down 2.1%.

A crash between an Air Canada Express jet and a fire

truck at New York's LaGuardia injured dozens of passengers and

led to hundreds of flight cancellations at the start of the

working week, the latest disruption for airports and carriers

that have been knocked off-kilter by a weeks-long budget

standoff in Congress.

Still, shares of Air Canada ( ACDVF ) rose 3.1%, helping to send the

industrials sector 1.9% higher. Heavily weighted

financials were up 1.8%.

Just two of the 10 major sectors ended lower, including energy

. It lost 1.3% as the price of oil settled 10.3%

lower at $88.13 a barrel.